In the areas of construction and production, traditional consumables are replaced by technological plastics in various designs. They are distinguished by high technical and physical qualities, which allows them to confidently replace both wood and even metal. Nevertheless, wood raw materials have many advantages due to low purchase costs and environmental friendliness. The weak point of this material is considered to be strength. To increase this indicator, manufacturers use special processing methods to increase stiffness, density and overall resistance to mechanical damage. However, hardwoods initially have these properties, often eliminating the need for special heat treatments.
Features of hard wood
Typically, the quality of such rocks is evaluated by three indicators - density, Brinnel hardness and the rigidity of the transverse cut. On average, the density of such wood is about 1200-1400 kg / m 3 . As for Brinell hardness, this value can reach 3.5 kgf / mm 2 , and the rigidity of the transverse cut - 80 MPa. Again, these indicators are characteristic of trees familiar to Russian conditions, and exotic species can have significantly superior characteristics. Which wood species are hard in the temperate zone? Usually emit oak, beech, ash and some types of hornbeam. It is important to consider that, along with a positive quality in the form of hardness, such trees also differ in negative properties. It has already been said that in order to improve performance, lumber can be subjected to additional processing. Sometimes, to obtain special physical characteristics, hardwood is also subjected to similar operations. And here a serious problem appears, because many breeds, due to their high density, cannot stand the processes of grinding, impregnation, and especially drying. Often cracks, chips and other manifestations of the deformation of the structure are formed.
Hardwood Classifications
There are species growing in the temperate zone, and exotic trees. There is also a classification for deciduous and conifers. Although most hardwoods still belong to hardwoods, varieties with high density and stiffness characteristics are also found among the needles. As for the rocks of the temperate zone, maple, boxwood, briar and the mentioned hornbeam can be attributed to them. Coniferous hardwoods are the most common here. Which of them have the most pronounced hardness indicators? In this case, larch, yew, juniper and lawson deserve attention. Hard breeds are also found among the usual fruit trees - in this category stands a forest apple, sour, pear, mountain ash and some types of walnuts. As for exotic breeds, they demonstrate the highest rates of hardness and density. Of particular interest here are red and lemon trees, rosewood, eucalyptus, etc. Now it is worth considering in more detail the hardest species of trees.
Red tree
In Russia, this breed is the most popular, as it can be purchased on the open market. This is a tropical tree, which is characterized by high hardness, as well as the original texture on the cut. Freshly sawn wood has a yellowish-red hue, but over time it gives way to darker tones, which gives the material nobleness. Accordingly, the consumer appreciates not only the technical, but also the decorative properties of this tree. It should be noted that from the point of view of pronounced decorative qualities, hardwood also includes bacout and boxwood. Moreover, these breeds are used not only as finishing materials, but can also replace individual decorative details in jewelry and technical devices. But mahogany is also distinguished by the ease of machining. The density of this breed is not so high compared to many solid materials of tropical origin, therefore, this raw material is very popular in furniture factories.
Iron tree
If heavy-duty plastics can replace iron due to their strength, then this breed is not only able in some areas to take the place of an element resistant to mechanical loads, but also meet increased requirements in terms of environmental resistance. The concept of iron tree includes a whole group of species that mainly grow in the countries of the Asian region and in Australia. The classic representative of the group is Persian parrotia. This species is common in relict forests, where local residents from ancient times made handles for knives and axes from it. Today, “iron” hardwood is under the protection of UNESCO. This breed, in particular, has aesthetic value, which leads to great interest in it from the market.
Merbau
This is not the hardest, but in the aggregate of other operational qualities, we can say the most practical breed. Previously, this tree was used in the construction of marine vessels. This is due to the fact that the material is resistant to moisture and also does not dry out. Therefore, merbau can be stored for a long time, after which it is subjected to heat treatments and used in construction. As already noted, trees related to hardwood, like hornbeam or beech, practically do not tolerate additional processing. But merbau steadfastly endures the traditional methods of exposure in order to improve individual performance.
White Acacia
The hardest breed in Russia, which is valued not only for its strength, but also for its resistance to biological destruction processes. In addition, acacia of this species is well polished and does not crack during prolonged use. Subject to preventive measures, wood also does not undergo minor mechanical damage. By the way, this species is superior in technical characteristics to such hardwoods as oak and ash.
Lignum vitae
The hardness of this tree is one of the highest in the whole world. Suffice it to say that the material optimally copes with its tasks when used in the form of bearings, bushings and brackets. In the Navy, wood of this breed was often used as a material for the deck. But as lumber, a backout is also valued for other reasons. It does not lend itself to deforming processes under the influence of external negative factors. It can be both chemical and physical effects, which do not have a destructive effect on the structure. There are other hardwoods that are also resistant to extreme loads. But the unique quality of the backout is the balanced combination of large mass and density.
Hardwood Application
Most of this material is used in construction. Wood in one form or another can be used both as a basis for structures and as a finish. Individual breeds are also used in the fields of machine and instrument engineering. Of these, separate functional elements are performed with the expectation of long-term use - and this can be both temporary consumables and durable parts of structures. These are the main, but not all areas in which high-strength wood species are used. Soft, hard breeds, as well as types of wood with average density indices, can also be used for medical purposes. In this case, hardness is not so important. The fact is that many exotic breeds contain resins that are unique in quality. The preparation of therapeutic mixtures for internal and external use, in particular, allows you to fight diseases of the joints, respiratory organs, etc.
Conclusion
Manufacturers of building materials are well acquainted with the rule that increasing one technical and operational property almost always entails minimizing other qualities. In part, this law also applies to hardwoods, which, according to some characteristics, lose to soft species. The processes of biological destruction, physical deformation, as well as distortion of the texture are the main disadvantages of soft rocks used in the long-term format. But on the other hand, such wood has the advantage of being susceptible to additional treatments. Of course, in both categories there are exceptions, but the soft structure, due to its low density, is nevertheless more disposed to the formation of new properties artificially.